JWST/NIRCam coronagraphy: commissioning and first on-sky results
J. H. Girard, Jarron Leisenring, Jens Kammerer, Mario Gennaro, Marcia Rieke, John Stansberry, A. Rest, Eiichi Egami, Ben Sunnquist, Martha L. Boyer, Alicia Canipe, Matteo Correnti, B. Hilbert, Marshall D. Perrin, Laurent Pueyo, Rémi Soummer, Marsha Allen, H. Bushouse, Jonathan Aguilar, Brian Brooks, Dan Coe, Audrey DiFelice, D. A. Golimowski, G. Hartig, Dean C. Hines, Anton M. Koekemoer, Bryony Nickson, Nikolay Nikolov, Vera Platais, Nor Prizkal, Massimo Robberto, Anand Sivaramakrishnan, Sangmo Tony Sohn, Randal Telfer, Chi Rai Wu, Thomas G. Beatty, Michael Florian, Kevin Hainline, Doug Kelly, K. A. Misselt, Everett Schlawin, Fengwu Sun, Christina C. Williams, Christopher Willmer, Christopher C. Stark, Marie Ygouf, Aarynn L. Carter, Charles Beichman, Thomas P. Greene, Thomas L. Roellig, John Krist, Jéa Adams Redai, Jason Wang, Charles R. Clark, Dan Lewis, Malcolm Ferry
Abstract
In a cold and stable space environment, the James Webb Space Telescope (JWST or ”Webb”) reaches unprecedented sensitivities at wavelengths beyond 2 microns, serving most fields of astrophysics. It also extends the parameter space of high-contrast imaging in the near and mid-infrared. Launched in late 2021, JWST underwent a six month commissioning period. In this contribution we focus on the NIRCam Coronagraphy mode which was declared ”science ready” on July 10 2022, the last of the 17 JWST observing modes. Essentially, this mode enables the detection of fainter/redder/colder (less massive for a given age) self-luminous exoplanets as well as other faint astrophysical signal in the vicinity of any bright object (stars or galaxies). Here we describe some of the steps and hurdles the commissioning team went through to achieve excellent performances. Specifically, we focus on the Coronagraphic Suppression Verification activity. We were able to produce firm detections at 3.35µm of the white dwarf companion HD 114174 B which is at a separation of ' 0.500and a contrast of ' 10 magnitudes (104 fainter than the K∼5.3 host star). We compare these first on-sky images with our latest, most informed and realistic end-to-end simulations through the same pipeline. Additionally we provide information on how we succeeded with the target acquisition with all five NIRCam focal plane masks and their four corresponding wedged Lyot stops.